/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.geogebra.common.move.ggtapi.models.json;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;

// Note: this class was written without inspecting the non-free org.json sourcecode.
/**
 * A dense indexed sequence of values. Values may be any mix of
 * {@link JSONObject JSONObjects}, other {@link JSONArray JSONArrays}, Strings,
 * Booleans, Integers, Longs, Doubles, {@code null} or {@link JSONObject#NULL}.
 * Values may not be {@link Double#isNaN() NaNs}, {@link Double#isInfinite()
 * infinities}, or of any type not listed here.
 *
 * <p>
 * {@code JSONArray} has the same type coercion behavior and optional/mandatory
 * accessors as {@link JSONObject}. See that class' documentation for details.
 *
 * <p>
 * <strong>Warning:</strong> this class represents null in two incompatible
 * ways: the standard Java {@code null} reference, and the sentinel value
 * {@link JSONObject#NULL}. In particular, {@code get} fails if the requested
 * index holds the null reference, but succeeds if it holds
 * {@code JSONObject.NULL}.
 *
 * <p>
 * Instances of this class are not thread safe. Although this class is nonfinal,
 * it was not designed for inheritance and should not be subclassed. In
 * particular, self-use by overridable methods is not specified. See
 * <i>Effective Java</i> Item 17, "Design and Document or inheritance or else
 * prohibit it" for further information.
 */
public class JSONArray {
	private final List<Object> values;

	/**
	 * Creates a {@code JSONArray} with no values.
	 */
	public JSONArray() {
		values = new ArrayList<>();
	}

	/**
	 * Creates a new {@code JSONArray} by copying all values from the given
	 * collection. Accept a raw type for API compatibility
	 * 
	 * @param copyFrom
	 *            a collection whose values are of supported types. Unsupported
	 *            values are not permitted and will yield an array in an
	 *            inconsistent state.
	 */
	public JSONArray(Collection copyFrom) {
		this();
		if (copyFrom != null) {
			for (Iterator it = copyFrom.iterator(); it.hasNext();) {
				put(JSONObject.wrap(it.next()));
			}
		}
	}

	/**
	 * Creates a new {@code JSONArray} with values from the next array in the
	 * tokener.
	 *
	 * @param readFrom
	 *            a tokener whose nextValue() method will yield a
	 *            {@code JSONArray}.
	 * @throws JSONException
	 *             if the parse fails or doesn't yield a {@code JSONArray}.
	 */
	public JSONArray(JSONTokener readFrom) throws JSONException {
		/*
		 * Getting the parser to populate this could get tricky. Instead, just
		 * parse to temporary JSONArray and then steal the data from that.
		 */
		Object object = readFrom.nextValue();
		if (object instanceof JSONArray) {
			values = ((JSONArray) object).values;
		} else {
			throw JSON.typeMismatch(object, "JSONArray");
		}
	}

	/**
	 * Creates a new {@code JSONArray} with values from the JSON string.
	 *
	 * @param json
	 *            a JSON-encoded string containing an array.
	 * @throws JSONException
	 *             if the parse fails or doesn't yield a {@code
	 *     JSONArray}.
	 */
	public JSONArray(String json) throws JSONException {
		this(new JSONTokener(json));
	}

	/**
	 * Creates a new {@code JSONArray} with values from the given primitive
	 * array.
	 *
	 * public JSONArray(Object array) throws JSONException { if
	 * (!array.getClass().isArray()) { throw new JSONException(
	 * "Not a primitive array: " + array.getClass()); } final int length =
	 * Array.getLength(array); values = new ArrayList<Object>(length); for (int
	 * i = 0; i < length; ++i) { put(JSONObject.wrap(Array.get(array, i))); } }
	 */

	/**
	 * Returns the number of values in this array.
	 * 
	 * @return length
	 */
	public int length() {
		return values.size();
	}

	/**
	 * Appends {@code value} to the end of this array.
	 * 
	 * @param value
	 *            boolean value
	 *
	 * @return this array.
	 */
	public JSONArray put(boolean value) {
		values.add(value);
		return this;
	}

	/**
	 * Appends {@code value} to the end of this array.
	 *
	 * @param value
	 *            a finite value. May not be {@link Double#isNaN() NaNs} or
	 *            {@link Double#isInfinite() infinities}.
	 * @return this array.
	 */
	public JSONArray put(double value) throws JSONException {
		values.add(JSON.checkDouble(value));
		return this;
	}

	/**
	 * Appends {@code value} to the end of this array.
	 *
	 * @return this array.
	 */
	public JSONArray put(int value) {
		values.add(value);
		return this;
	}

	/**
	 * Appends {@code value} to the end of this array.
	 * 
	 * @param value
	 *            value to add
	 *
	 * @return this array.
	 */
	public JSONArray put(long value) {
		values.add(value);
		return this;
	}

	/**
	 * Appends {@code value} to the end of this array.
	 *
	 * @param value
	 *            a {@link JSONObject}, {@link JSONArray}, String, Boolean,
	 *            Integer, Long, Double, {@link JSONObject#NULL}, or
	 *            {@code null}. May not be {@link Double#isNaN() NaNs} or
	 *            {@link Double#isInfinite() infinities}. Unsupported values are
	 *            not permitted and will cause the array to be in an
	 *            inconsistent state.
	 * @return this array.
	 */
	public JSONArray put(Object value) {
		values.add(value);
		return this;
	}

	/**
	 * Same as {@link #put}, with added validity checks.
	 */
	void checkedPut(Object value) throws JSONException {
		if (value instanceof Number) {
			JSON.checkDouble(((Number) value).doubleValue());
		}
		put(value);
	}

	/**
	 * Sets the value at {@code index} to {@code value}, null padding this array
	 * to the required length if necessary. If a value already exists at {@code
	 * index}, it will be replaced.
	 *
	 * @return this array.
	 */
	public JSONArray put(int index, boolean value) throws JSONException {
		return put(index, (Boolean) value);
	}

	/**
	 * Sets the value at {@code index} to {@code value}, null padding this array
	 * to the required length if necessary. If a value already exists at {@code
	 * index}, it will be replaced.
	 *
	 * @param value
	 *            a finite value. May not be {@link Double#isNaN() NaNs} or
	 *            {@link Double#isInfinite() infinities}.
	 * @return this array.
	 */
	public JSONArray put(int index, double value) throws JSONException {
		return put(index, (Double) value);
	}

	/**
	 * Sets the value at {@code index} to {@code value}, null padding this array
	 * to the required length if necessary. If a value already exists at {@code
	 * index}, it will be replaced.
	 *
	 * @return this array.
	 */
	public JSONArray put(int index, int value) throws JSONException {
		return put(index, (Integer) value);
	}

	/**
	 * Sets the value at {@code index} to {@code value}, null padding this array
	 * to the required length if necessary. If a value already exists at {@code
	 * index}, it will be replaced.
	 *
	 * @return this array.
	 */
	public JSONArray put(int index, long value) throws JSONException {
		return put(index, (Long) value);
	}

	/**
	 * Sets the value at {@code index} to {@code value}, null padding this array
	 * to the required length if necessary. If a value already exists at {@code
	 * index}, it will be replaced.
	 *
	 * @param value
	 *            a {@link JSONObject}, {@link JSONArray}, String, Boolean,
	 *            Integer, Long, Double, {@link JSONObject#NULL}, or
	 *            {@code null}. May not be {@link Double#isNaN() NaNs} or
	 *            {@link Double#isInfinite() infinities}.
	 * @return this array.
	 */
	public JSONArray put(int index, Object value) throws JSONException {
		if (value instanceof Number) {
			// deviate from the original by checking all Numbers, not just
			// floats & doubles
			JSON.checkDouble(((Number) value).doubleValue());
		}
		while (values.size() <= index) {
			values.add(null);
		}
		values.set(index, value);
		return this;
	}

	/**
	 * Returns true if this array has no value at {@code index}, or if its value
	 * is the {@code null} reference or {@link JSONObject#NULL}.
	 * 
	 * @param index
	 *            index
	 * @return whether value at index is null
	 */
	public boolean isNull(int index) {
		Object value = opt(index);
		return value == null || value == JSONObject.NULL;
	}

	/**
	 * Returns the value at {@code index}.
	 * 
	 * @param index
	 *            index
	 * @return value at index
	 *
	 * @throws JSONException
	 *             if this array has no value at {@code index}, or if that value
	 *             is the {@code null} reference. This method returns normally
	 *             if the value is {@code JSONObject#NULL}.
	 */
	public Object get(int index) throws JSONException {
		try {
			Object value = values.get(index);
			if (value == null) {
				throw new JSONException("Value at " + index + " is null.");
			}
			return value;
		} catch (IndexOutOfBoundsException e) {
			throw new JSONException("Index " + index + " out of range [0.."
					+ values.size() + ")");
		}
	}

	/**
	 * Returns the value at {@code index}, or null if the array has no value at
	 * {@code index}.
	 * 
	 * @param index
	 *            index
	 * @return value at index or null
	 */
	public Object opt(int index) {
		if (index < 0 || index >= values.size()) {
			return null;
		}
		return values.get(index);
	}

	/**
	 * Removes and returns the value at {@code index}, or null if the array has
	 * no value at {@code index}.
	 * 
	 * @param index
	 *            index
	 * @return value at index
	 */
	public Object remove(int index) {
		if (index < 0 || index >= values.size()) {
			return null;
		}
		return values.remove(index);
	}

	/**
	 * Returns the value at {@code index} if it exists and is a boolean or can
	 * be coerced to a boolean.
	 * 
	 * @param index
	 *            index
	 * @return boolean value at index
	 *
	 * @throws JSONException
	 *             if the value at {@code index} doesn't exist or cannot be
	 *             coerced to a boolean.
	 */
	public boolean getBoolean(int index) throws JSONException {
		Object object = get(index);
		Boolean result = JSON.toBoolean(object);
		if (result == null) {
			throw JSON.typeMismatch(index, object, "boolean");
		}
		return result;
	}

	/**
	 * Returns the value at {@code index} if it exists and is a boolean or can
	 * be coerced to a boolean. Returns false otherwise.
	 * 
	 * @param index
	 *            index
	 * @return boolean value at index, false if not set
	 */
	public boolean optBoolean(int index) {
		return optBoolean(index, false);
	}

	/**
	 * Returns the value at {@code index} if it exists and is a boolean or can
	 * be coerced to a boolean. Returns {@code fallback} otherwise.
	 * 
	 * @param index
	 *            index
	 * @param fallback
	 *            fallback value
	 * @return boolean value at index or fallback
	 */
	public boolean optBoolean(int index, boolean fallback) {
		Object object = opt(index);
		Boolean result = JSON.toBoolean(object);
		return result != null ? result : fallback;
	}

	/**
	 * Returns the value at {@code index} if it exists and is a double or can be
	 * coerced to a double.
	 * 
	 * @param index
	 *            index
	 * @return double value at index
	 *
	 * @throws JSONException
	 *             if the value at {@code index} doesn't exist or cannot be
	 *             coerced to a double.
	 */
	public double getDouble(int index) throws JSONException {
		Object object = get(index);
		Double result = JSON.toDouble(object);
		if (result == null) {
			throw JSON.typeMismatch(index, object, "double");
		}
		return result;
	}

	/**
	 * Returns the value at {@code index} if it exists and is a double or can be
	 * coerced to a double. Returns {@code NaN} otherwise.
	 * 
	 * @param index
	 *            index
	 * @return double value at index or NaN
	 */
	public double optDouble(int index) {
		return optDouble(index, Double.NaN);
	}

	/**
	 * Returns the value at {@code index} if it exists and is a double or can be
	 * coerced to a double. Returns {@code fallback} otherwise.
	 * 
	 * @param index
	 *            index
	 * @param fallback
	 *            fallback
	 * @return double value at index or fallback
	 */
	public double optDouble(int index, double fallback) {
		Object object = opt(index);
		Double result = JSON.toDouble(object);
		return result != null ? result : fallback;
	}

	/**
	 * Returns the value at {@code index} if it exists and is an int or can be
	 * coerced to an int.
	 * 
	 * @param index
	 *            index
	 * @return int value at index
	 *
	 * @throws JSONException
	 *             if the value at {@code index} doesn't exist or cannot be
	 *             coerced to a int.
	 */
	public int getInt(int index) throws JSONException {
		Object object = get(index);
		Integer result = JSON.toInteger(object);
		if (result == null) {
			throw JSON.typeMismatch(index, object, "int");
		}
		return result;
	}

	/**
	 * Returns the value at {@code index} if it exists and is an int or can be
	 * coerced to an int. Returns 0 otherwise.
	 * 
	 * @param index
	 *            index
	 * @return int value or 0
	 */
	public int optInt(int index) {
		return optInt(index, 0);
	}

	/**
	 * Returns the value at {@code index} if it exists and is an int or can be
	 * coerced to an int. Returns {@code fallback} otherwise.
	 * 
	 * @param index
	 *            index
	 * @param fallback
	 *            fallback
	 * @return int value at index or fallback
	 */
	public int optInt(int index, int fallback) {
		Object object = opt(index);
		Integer result = JSON.toInteger(object);
		return result != null ? result : fallback;
	}

	/**
	 * Returns the value at {@code index} if it exists and is a long or can be
	 * coerced to a long.
	 * 
	 * @param index
	 *            index
	 * @return long value at index
	 *
	 * @throws JSONException
	 *             if the value at {@code index} doesn't exist or cannot be
	 *             coerced to a long.
	 */
	public long getLong(int index) throws JSONException {
		Object object = get(index);
		Long result = JSON.toLong(object);
		if (result == null) {
			throw JSON.typeMismatch(index, object, "long");
		}
		return result;
	}

	/**
	 * Returns the value at {@code index} if it exists and is a long or can be
	 * coerced to a long. Returns 0 otherwise.
	 * 
	 * @param index
	 *            index
	 * @return long value at index or 0
	 */
	public long optLong(int index) {
		return optLong(index, 0L);
	}

	/**
	 * Returns the value at {@code index} if it exists and is a long or can be
	 * coerced to a long. Returns {@code fallback} otherwise.
	 * 
	 * @param index
	 *            index
	 * @param fallback
	 *            fallback
	 * @return long value at index or fallback
	 */
	public long optLong(int index, long fallback) {
		Object object = opt(index);
		Long result = JSON.toLong(object);
		return result != null ? result : fallback;
	}

	/**
	 * Returns the value at {@code index} if it exists, coercing it if
	 * necessary.
	 * 
	 * @param index
	 *            index
	 * @return string value at index
	 *
	 * @throws JSONException
	 *             if no such value exists.
	 */
	public String getString(int index) throws JSONException {
		Object object = get(index);
		String result = JSON.toString(object);
		if (result == null) {
			throw JSON.typeMismatch(index, object, "String");
		}
		return result;
	}

	/**
	 * Returns the value at {@code index} if it exists, coercing it if
	 * necessary. Returns the empty string if no such value exists.
	 * 
	 * @param index
	 *            index
	 * @return string value at index or empty string
	 */
	public String optString(int index) {
		return optString(index, "");
	}

	/**
	 * Returns the value at {@code index} if it exists, coercing it if
	 * necessary. Returns {@code fallback} if no such value exists.
	 * 
	 * @param index
	 *            index
	 * @param fallback
	 *            fallback
	 * @return string value at index or fallback
	 */
	public String optString(int index, String fallback) {
		Object object = opt(index);
		String result = JSON.toString(object);
		return result != null ? result : fallback;
	}

	/**
	 * Returns the value at {@code index} if it exists and is a {@code
	 * JSONArray}.
	 * 
	 * @param index
	 *            index
	 * @return array value at index
	 *
	 * @throws JSONException
	 *             if the value doesn't exist or is not a {@code
	 *     JSONArray}.
	 */
	public JSONArray getJSONArray(int index) throws JSONException {
		Object object = get(index);
		if (object instanceof JSONArray) {
			return (JSONArray) object;
		}
		throw JSON.typeMismatch(index, object, "JSONArray");
	}

	/**
	 * Returns the value at {@code index} if it exists and is a {@code
	 * JSONArray}. Returns null otherwise.
	 * 
	 * @param index
	 *            index
	 * @return array value at index
	 */
	public JSONArray optJSONArray(int index) {
		Object object = opt(index);
		return object instanceof JSONArray ? (JSONArray) object : null;
	}

	/**
	 * Returns the value at {@code index} if it exists and is a {@code
	 * JSONObject}.
	 * 
	 * @param index
	 *            index
	 * @return object value at index
	 *
	 * @throws JSONException
	 *             if the value doesn't exist or is not a {@code
	 *     JSONObject}.
	 */
	public JSONObject getJSONObject(int index) throws JSONException {
		Object object = get(index);
		if (object instanceof JSONObject) {
			return (JSONObject) object;
		}
		throw JSON.typeMismatch(index, object, "JSONObject");
	}

	/**
	 * Returns the value at {@code index} if it exists and is a {@code
	 * JSONObject}. Returns null otherwise.
	 * 
	 * @param index
	 *            index
	 * @return object value at index or null
	 */
	public JSONObject optJSONObject(int index) {
		Object object = opt(index);
		return object instanceof JSONObject ? (JSONObject) object : null;
	}

	/**
	 * Returns a new object whose values are the values in this array, and whose
	 * names are the values in {@code names}. Names and values are paired up by
	 * index from 0 through to the shorter array's length. Names that are not
	 * strings will be coerced to strings. This method returns null if either
	 * array is empty.
	 * 
	 * @param names
	 *            keys in resulting object
	 * @return JSON object with given keys, using this array as values
	 */
	public JSONObject toJSONObject(JSONArray names) throws JSONException {
		JSONObject result = new JSONObject();
		int length = Math.min(names.length(), values.size());
		if (length == 0) {
			return null;
		}
		for (int i = 0; i < length; i++) {
			String name = JSON.toString(names.opt(i));
			result.put(name, opt(i));
		}
		return result;
	}

	/**
	 * Returns a new string by alternating this array's values with {@code
	 * separator}. This array's string values are quoted and have their special
	 * characters escaped. For example, the array containing the strings '12"
	 * pizza', 'taco' and 'soda' joined on '+' returns this:
	 * 
	 * <pre>
	 * "12\" pizza" + "taco" + "soda"
	 * </pre>
	 * 
	 * @param separator
	 *            separator
	 * @return array items joined using separator
	 */
	public String join(String separator) throws JSONException {
		JSONStringer stringer = new JSONStringer();
		stringer.open(JSONStringer.Scope.NULL, "");
		for (int i = 0, size = values.size(); i < size; i++) {
			if (i > 0) {
				stringer.out.append(separator);
			}
			stringer.value(values.get(i));
		}
		stringer.close(JSONStringer.Scope.NULL, JSONStringer.Scope.NULL, "");
		return stringer.out.toString();
	}

	/**
	 * Encodes this array as a compact JSON string, such as:
	 * 
	 * <pre>
	 * [94043,90210]
	 * </pre>
	 */
	@Override
	@SuppressFBWarnings({ "NP_TOSTRING_COULD_RETURN_NULL",
			"API specifies this" })
	public String toString() {
		try {
			JSONStringer stringer = new JSONStringer();
			writeTo(stringer);
			return stringer.toString();
		} catch (JSONException e) {
			return null;
		}
	}

	/**
	 * Encodes this array as a human readable JSON string for debugging, such
	 * as:
	 * 
	 * <pre>
	 * [
	 *     94043,
	 *     90210
	 * ]
	 * </pre>
	 *
	 * @param indentSpaces
	 *            the number of spaces to indent for each level of nesting.
	 * @return this array as formatted string
	 */
	public String toString(int indentSpaces) throws JSONException {
		JSONStringer stringer = new JSONStringer(indentSpaces);
		writeTo(stringer);
		return stringer.toString();
	}

	void writeTo(JSONStringer stringer) throws JSONException {
		stringer.array();
		for (Object value : values) {
			stringer.value(value);
		}
		stringer.endArray();
	}

	@Override
	public boolean equals(Object o) {
		return o instanceof JSONArray && ((JSONArray) o).values.equals(values);
	}

	@Override
	public int hashCode() {
		// diverge from the original, which doesn't implement hashCode
		return values.hashCode();
	}
}